Skies over eastern China remained hazy on October 18, 2011. The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite took this picture the same day.

Over China’s coastal plain south of Beijing, haze forms a giant, nearly opaque arc that terminates over Bo Hai. Although agricultural fires probably play a role in the formation of the haze, it more likely results from urban and industrial pollution in this densely populated area.